Tire with an integrated rfid and tpms sensor

ABSTRACT

A pneumatic tire with a radio frequency identification and tire pressure monitoring system sensor combination includes a pneumatic tire. The tire includes a pair of bead areas, a ground-contacting tread disposed radially outwardly of the pair of bead areas, a pair of sidewalls, in which each sidewall extends from a respective bead area to the tread, a carcass extending toroidally between each of the bead areas radially inwardly of the tread, and an innerliner formed on an inside surface of the carcass. An integrated RFID and TPMS sensor is mounted on the innerliner and includes an RFID tag. The RFID tag includes an integrated circuit carried on a printed circuit board. The printed circuit board is formed with at least one opening to facilitate secure mounting of the circuit board to the innerliner. The integrated RFID and TMPS sensor also includes a TPMS sensor mounted on the RFID tag.

FIELD OF THE INVENTION

The invention relates to tires. More particularly, the invention relatesto the monitoring of tire pressure and tire identification.Specifically, the invention is directed to a tire that includes a sensorwith optimum mounting and structure for transmission of tire pressuredata and tire identification information by radio frequency.

BACKGROUND OF THE INVENTION

Pneumatic tires have been widely employed. Such tires include a pair ofbeads that are mounted on a wheel or rim. Each one of pair of sidewallsextends from a respective bead to a ground-engaging tread. A carcass,which is made of one or more plies, toroidally extends between the beadsto reinforce the sidewalls and the tread. An innerliner is formed on theinside surface of the carcass. The wheel cooperates with the innerlinerto define an interior or tire cavity that is inflated with air.

It has been desirable to provide such pneumatic tires with an electronicdevice that enables information about the tire to be transmitted to anexternal device for tracking of certain parameters and identification ofthe tire during its lifetime. One such electronic device is a radiofrequency identification (RFID) device, sometimes referred to as an RFIDtag.

Most RFID tags include an integrated circuit for storing and processinginformation and an antenna for receiving and transmitting a signal to anexternal reader using a radio frequency. The antenna is electronicallyconnected to the integrated circuit and typically is carried on asubstrate with the integrated circuit, such as a circuit board.

In the prior art, RFID tags were attached to the exterior of a sidewallof a pneumatic tire. The exterior of a tire sidewall provides aconvenient location that enables strong transmission of the signal fromthe RFID tag to an RFID reader, which is separate from the tire.However, the RFID tag may incur potential damage when it is attached tothe exterior of a tire sidewall. To reduce such potential damage, it hasbecome desirable to attach the RFID tag to and interior structure of thetire. However, such interior attachment poses challenges in transmissionof the signal, as the tire materials interfere with the transmission.

In addition, it is desirable to monitor certain parameters, such as thepressure in the tire cavity, the temperature in the tire cavity and/orthe temperature in the tread or another tire component, and to transmitdata for those parameters to a device that can record and/or display thedata. To this end, tire pressure monitoring systems (TPMS) have beendeveloped. Due to power and communication requirements of TPMS sensors,TPMS units have been separate from RFID tags. However, mounting ofseparate TPMS sensors and RFID tags is undesirable, particularly fortires that may be employed at high speeds. For example, high vehiclespeeds, such as speeds up to 200 miles per hour (mph), result in highrotational speeds for the tire. Such high rotational speeds andaccompanying increases in tire temperature due to friction requireoptimum mounting of any components to the tire.

Moreover, most TPMS units employ batteries to power the sensors andtransmit measured data. Such use of battery power undesirably limits therange of the signal from the TPMS unit and how frequently data may besent, as a longer range and/or more frequent transmission may severelydecrease the life of the system.

As a result, there is a need in the art for a tire that includes a TPMSunit and an RFID tag which minimizes the components that are mounted tothe tire, while employing an optimum structure for use at high speeds.

SUMMARY OF THE INVENTION

According to an aspect of an exemplary embodiment of the invention, apneumatic tire with a radio frequency identification (RFID) and tirepressure monitoring system (TPMS) sensor combination includes apneumatic tire. The pneumatic tire includes a pair of bead areas, aground-contacting tread disposed radially outwardly of the pair of beadareas, a pair of sidewalls, in which each sidewall extends from arespective bead area to the tread, a carcass extending toroidallybetween each of the bead areas radially inwardly of the tread, and aninnerliner formed on an inside surface of the carcass. An integratedRFID and TPMS sensor is mounted on the innerliner and includes an RFIDtag. The RFID tag includes an integrated circuit that is carried on aprinted circuit board. The printed circuit board is formed with at leastone opening to facilitate secure mounting of the circuit board to theinnerliner. The integrated RFID and TPMS sensor includes a TPMS sensormounted on the RFID tag.

Definitions

“Axial” and “axially” mean lines or directions that are parallel to theaxis of rotation of the tire.

“Axially inward” and “axially inwardly” refer to an axial direction thatis toward the axial center of the tire.

“Axially outward” and “axially outwardly” refer to an axial directionthat is away from the axial center of the tire.

“Circumferential” means lines or directions extending along theperimeter of the surface of the annular tread perpendicular to the axialdirection.

“Inboard” refers to the axial inner surface of the tire as mounted onthe vehicle.

“Innerliner” means the layer or layers of elastomer or other materialthat form the inside surface of a tubeless tire and that contain theinflating fluid within the tire.

“Outboard” refers to the axial outer surface of the tire as mounted on avehicle.

“Radial” and “radially” mean lines or directions that are perpendicularto the axis of rotation of the tire.

“Radially inward” and “radially inwardly” refer to a radial directionthat is toward the central axis of rotation of the tire.

“Radially outward” and “radially outwardly” refer to a radial directionthat is away from the central axis of rotation of the tire.

“RFID” means radio frequency identification.

“TPMS” means a tire pressure monitoring system.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by way of example and with reference tothe accompanying drawings, in which:

FIG. 1 is a cross-sectional view of an exemplary embodiment of apneumatic tire with an RFID and TPMS sensor of the present invention;

FIG. 2 is a top view of an exemplary integrated RFID and TPMS sensor;

FIG. 3 is a bottom view of the integrated RFID and TPMS sensor shown inFIG. 2;

FIG. 4 is a top view of the structure shown in FIG. 2 including acoating for mounting the sensor to a tire prior to curing of the tire;

FIG. 5 is a perspective view of the pneumatic tire with an RFID and TPMSsensor shown in FIG. 1, configured for mounting to the tire before tirecuring, and shown prior to tire curing;

FIG. 6 is a perspective view of the pneumatic tire with an RFID and TPMSsensor shown in FIG. 5 after curing of the tire;

FIG. 7 is a perspective view of the pneumatic tire with an RFID and TPMSsensor shown in FIG. 1, configured for mounting to the tire after tirecuring, and shown being encapsulated with a radio-frequency conductivecompound, caulk or adhesive; and

FIG. 8 is a perspective view of the pneumatic tire with an RFID and TPMSsensor shown in FIG. 7 after curing of the radio-frequency conductivecompound, caulk or adhesive.

Similar numerals refer to similar parts throughout the drawings.

DETAILED DESCRIPTION OF THE INVENTION

An exemplary embodiment of a pneumatic tire with an RFID and TPMS sensorof the present invention is shown in FIGS. 1 through 8 and is indicatedgenerally at 10. Referring to FIG. 1, the invention includes a pneumatictire 12, which in turn includes a pair of bead areas 14 and a respectivebead core 16 embedded in each bead area. A respective sidewall 18extends radially outward from each bead area 14 to a ground-contactingtread 20. The tire 12 is reinforced by a carcass 22 that toroidallyextends from one of the bead areas 12 to the other one of the beadareas. The carcass 20 includes at least one ply 24 that preferably windsaround each bead core 16. A belt reinforcement package 26 is disposedbetween the carcass 22 and the tread 20. An innerliner 28 is formed onthe inside surface of the carcass 22. A tire cavity 30 is disposedinwardly of the innerliner 28. When the tire 12 is mounted on a wheel(not shown) of a vehicle, as known in the art, the innerliner 28cooperates with the wheel to render the tire cavity 30 airtight.

An integrated RFID and TPMS sensor is indicated at 32 and is mounted onthe innerliner 28 of the tire 12 as will be described in greater detailbelow. The RFID and TPMS sensor 32 preferably is mounted on theinnerliner 28 in a lower sidewall area 33, just above the bead area 14.In this manner, the RFID and TPMS sensor 32 is disposed in the tirecavity 30.

With reference now to FIGS. 2 and 3, an exemplary embodiment of the RFIDand TPMS sensor 32 includes an RFID tag 34, which in turn includes anintegrated circuit 36. The integrated circuit 36 is carried on a printedcircuit board 38 and processes and stores data for the tire 12. Moreparticularly, the integrated circuit 36 includes electronic memorycapacity for storing identification (ID) information for each tire 12,known as tire ID information. The tire ID information may includemanufacturing information for the tire 12, such as: the tire type; tiremodel; size information, such as rim size, width, and outer diameter;manufacturing location; manufacturing date; a treadcap code thatincludes or correlates to a compound identification; and a mold codethat includes or correlates to a tread structure identification. Thetire ID information may also include a service history or otherinformation to identify specific features and parameters of each tire12, as well as mechanical characteristics of the tire, such as corneringparameters, spring rate, load-inflation relationship, and the like. Suchtire identification enables correlation of the measured tire parametersand the specific tire 12 to provide local or central tracking of thetire, its current condition, and/or its condition over time.

The integrated circuit 36 also modulates and demodulates a radiofrequency signal for communication with an external reader (not shown)through an antenna 40. The antenna 40 includes two antenna wires 42 aand 42 b. Each antenna wire 42 a and 42 b includes a first end 44 a and44 b, respectively, which is electronically connected to the integratedcircuit 36 at a respective connection point 46 a and 46 b. At theconnection point 46 a and 46 b, each respective antenna wire 42 a and 42b is mounted to the printed circuit board 38. The antenna 40 receivesand transmits a signal to the external reader using a radio frequency,thus facilitating communication between the RFID tag and the reader.Preferably, the radio frequency is an ultra-high frequency (UHF) radiofrequency. In addition, each antenna wire 42 a and 42 b preferably isoriented to extend in a circumferential direction of the tire 12.

The printed circuit board 38 preferably is also formed with at least oneopening 48, and more preferably, with a plurality of openings. Theopenings 48 facilitate secure mounting of the circuit board 38 and thusthe RFID and TPMS sensor 32 to the tire innerliner 28, as will bedescribed in greater detail below. To enable secure mounting of the RFIDand TPMS sensor 32 to the tire innerliner 28 without compromising theintegrity of the innerliner, the printed circuit board 28 alsopreferably includes a width W that is about 15.9 millimeters (mm) and aheight H that is just over about half of the width, or about 9.2 mm. Foroptimum communication with an external reader, while also providingsecure mounting to the tire innerliner 28, a length of each wire 42 aand 42 b of the antenna 40 preferably is about 36 mm.

A TPMS sensor 50 is mounted on the RFID tag 34, and thus is inelectronic communication with the integrated circuit 36 and the antenna40. The TPMS sensor 50 includes a pressure sensor that measures thepressure in the tire cavity 30. The TPMS sensor 50 may also include oneor more temperature sensors that measure the temperature within the tirecavity 30 and/or another component of the tire 12. The TPMS sensor 50may correlate the pressure and temperature measurements. Other sensorsmay also be mounted on the RFID tag 34, such as a stress sensor, astrain sensor, vibration sensor, accelerometer, and the like.

The integrated RFID and TPMS sensor 32 is a passive unit. Moreparticularly, the antenna 40 communicates with an external readerthrough a UHF radio frequency, as described above. For optimum signaltransmission, the antenna wire 42 extends in a circumferential directionof the tire 12. Such an orientation, combined with a position in thelower sidewall area 33, enables the antenna 40 to efficiently send andreceive signals through the material of the tire 12. The integratedcircuit 36 also includes an energy harvester, which captures and thusharvests power from an electronic field of the UHF radio frequency. Theenergy harvester converts the radio frequency to direct electroniccurrent and charges a capacitor that is also included in the integratedcircuit 36. Optionally, the RFID and TPMS sensor 32 may be pre-chargedat a specific frequency using the antennas 46 and 48, which is turnedoff to enable the antennas to read the RFID and TPMS sensor. Inaddition, the energy harvester may alternatively capture and thusharvest optical energy, thermal energy and/or vibrational energy tocharge the capacitor.

The harvested energy enables the TPMS sensor 50 to obtain power in orderto take periodic pressure, temperature and/or other sensor measurements,as described above. Because the TPMS sensor 50 is mounted on the RFIDtag 34, the measured data is electronically communicated to theintegrated circuit 36, and may then be transmitted to the externalreader by the antenna 40. In this manner, the integrated RFID and TMPSsensor 32 transmits tire ID information from the RFID tag 34 andpressure, temperature and/or other measured data from the TPMS sensor 50to an external reader without the use of a battery.

While the circuit board 38 of the RFID and TPMS sensor 32 is roughlyrectangular in shape, it preferably is formed with at least one radiusedcorner 52. For example, the circuit board 38 may include two or morerounded or radiused corners 52. Each radiused corner 52 preferably isformed with a radius R that is approximately one-eighth of the circuitboard height H (FIG. 2). Such radiused corners 52 enable the RFID andTPMS sensor 32 to be securely mounted to the innerliner 28 of the tire12 without compromising the integrity of the innerliner.

Turning now to FIGS. 4 through 6, the integrated RFID and TPMS sensor 32may be mounted to the innerliner 28 before curing of the tire 12. Insuch a case, the circuit board 38 is encapsulated or coated in a rubberor polymer compound 54 that remains on the circuit board to protect theintegrated circuit 36 and enhance adhesive bonding of the RFID and TPMSsensor 32 to the tire innerliner 28. The TPMS sensor 50 is covered witha temporary protective material 56, such as tape, which preserves theintegrity of the pressure sensor during the curing process and may beremoved after curing.

With particular reference to FIG. 5, the RFID and TPMS sensor 32 ispositioned on the innerliner 28 in a lower sidewall area 33 with a stripof innerliner material 58. The strip of material 58 covers the RFID andTPMS sensor 32 to secure it to the innerliner 28. The tire 12 is thencured, securing the mounting of the RFID and TPMS sensor 32 to theinnerliner 28, as shown in FIG. 6. During curing, the openings 48 in thecircuit board 38 enable innerliner material 58 to pass into thestructure of the circuit board and provide integrated, secure mountingof the RFID and TPMS sensor 32 to the innerliner 28. A small opening 60is formed when the temporary protective material 56 is removed, enablingthe pressure sensor of the TPMS sensor 50 to be in direct communicationwith the tire cavity 30 (FIG. 1). Optionally, the pressure sensor of theTPMS sensor 50 may be removed from the remainder of the RFID and TPMSsensor 32 before the tire is cured, and then re-attached to the RFID andTPMS sensor through the opening 60 after the tire is cured.

Referring now to FIGS. 7 and 8, the RFID and TPMS sensor 32 may bemounted to the innerliner 28 after curing of the tire 12. For suchpost-cure mounting, the innerliner 28 is cleaned. Anelastomer-compatible adhesive 62, which is an appropriate adhesive thatbonds effectively between the RFID and TPMS sensor 32 and the innerliner28, is applied to the RFID and TPMS sensor. For example, aradio-frequency conductive compound, caulk or adhesive may be employedfor the adhesive 62. The RFID and TPMS sensor 32 with the adhesive 62 isapplied to the cleaned area of the innerliner 28, as shown in FIG. 8.Additional adhesive 62 is applied to the RFID and TPMS sensor 32 toencapsulate the sensor and secure its mounting to the innerliner 28, asshown in FIG. 8. The adhesive 62 is then allowed to cure. The openings48 in the circuit board 38 enable the adhesive 62 to pass into thestructure of the circuit board and provide integrated, secure mountingof the RFID and TPMS sensor 32 to the innerliner 28. Preferably, a smallopening 64 is formed when the adhesive 62 is applied, enabling thepressure sensor of the TPMS sensor 50 to be in direct communication withthe tire cavity 30 (FIG. 1).

In this manner, the pneumatic tire with an RFID and TPMS sensor 10 ofthe present invention employs a structure that enables operation at highvehicle speeds, such as up to about 200 mph. For example, the TPMSsensor 50 is mounted directly on the RFID tag 34 to form an integratedstructure. The openings 48 formed in the circuit board 38 enhance thestructural mounting of the integrated RFID and TPMS sensor 32 to thetire innerliner 28 for stability at high speeds.

The antenna wire 42 of the pneumatic tire and RFID and TPMS sensor 10 ofthe present invention extends in a circumferential direction of thetire, which combines with the position of the antenna 40 in the lowersidewall area 33 to enable efficient signal transmission. In addition,the small size of the circuit board 38 and its radiused corners 52maximize available circuit board space while not compromising theinnerliner 28 when increased stress and strain is incurred at highvehicle speeds. Moreover, as a passive unit that employs energyharvesting, the RFID and TPMS sensor 32 transmits tire ID informationfrom the RFID tag 34 and pressure, temperature and/or other sensor datafrom the TPMS sensor 50 to an external reader without the use of abattery. Data from additional sensors that are mounted on the RFID tag34, such as a stress sensor, a strain sensor, vibration sensor and/oraccelerometer, may be transmitted to an external reader without the useof a battery.

The present invention also includes a method of forming and/or using apneumatic tire with an RFID and TPMS sensor 10. The method includessteps in accordance with the description that is presented above andshown in FIGS. 1 through 8.

It is to be understood that the structure of the above-describedpneumatic tire with an RFID and TPMS sensor 10 may be altered orrearranged, or components known to those skilled in the art omitted oradded, without affecting the overall concept or operation of theinvention. The invention has been described with reference to apreferred embodiment. Potential modifications and alterations will occurto others upon a reading and understanding of this description. It is tobe understood that all such modifications and alterations are includedin the scope of the invention as set forth in the appended claims, orthe equivalents thereof.

What is claimed is:
 1. A pneumatic tire with a radio frequencyidentification (RFID) and tire pressure monitoring system (TPMS) sensorcombination, the combination comprising: a pneumatic tire including: apair of bead areas; a ground-contacting tread disposed radiallyoutwardly of the pair of bead areas; a pair of sidewalls, in which eachsidewall extends from a respective bead area to the tread; a carcassextending toroidally between each of the bead areas radially inwardly ofthe tread; an innerliner formed on an inside surface of the carcass; anintegrated RFID and TPMS sensor being mounted on the innerliner; theintegrated RFID and TPMS sensor including an RFID tag, the RFID tagincluding an integrated circuit being carried on a printed circuitboard, wherein the printed circuit board is formed with at least oneopening to facilitate secure mounting of the circuit board to theinnerliner; and the integrated RFID and TPMS sensor including a TPMSsensor mounted on the RFID tag.
 2. The pneumatic tire with a radiofrequency identification (RFID) and tire pressure monitoring system(TPMS) sensor combination of claim 1, wherein the integrated RFID andTPMS sensor is mounted on the innerliner at a lower sidewall area of theinnerliner.
 3. The pneumatic tire with a radio frequency identification(RFID) and tire pressure monitoring system (TPMS) sensor combination ofclaim 1, wherein the integrated RFID and TPMS sensor includes anantenna.
 4. The pneumatic tire with a radio frequency identification(RFID) and tire pressure monitoring system (TPMS) sensor combination ofclaim 3, wherein the antenna includes two wires that are eachelectronically connected to the integrated circuit at respectiveconnection points.
 5. The pneumatic tire with a radio frequencyidentification (RFID) and tire pressure monitoring system (TPMS) sensorcombination of claim 4, wherein each antenna wire extends in acircumferential direction of the tire.
 6. The pneumatic tire with aradio frequency identification (RFID) and tire pressure monitoringsystem (TPMS) sensor combination of claim 1, wherein the printed circuitboard is formed with at least one radiused corner.
 7. The pneumatic tirewith a radio frequency identification (RFID) and tire pressuremonitoring system (TPMS) sensor combination of claim 6, wherein the atleast one radiused corner includes a radius that is about one-eighth ofa height of the printed circuit board.
 8. The pneumatic tire with aradio frequency identification (RFID) and tire pressure monitoringsystem (TPMS) sensor combination of claim 1, wherein the integratedcircuit includes electronic memory capacity for storing identificationinformation for the tire.
 9. The pneumatic tire with a radio frequencyidentification (RFID) and tire pressure monitoring system (TPMS) sensorcombination of claim 1, wherein the TPMS sensor includes a pressuresensor.
 10. The pneumatic tire with a radio frequency identification(RFID) and tire pressure monitoring system (TPMS) sensor combination ofclaim 1, wherein the TPMS sensor includes at least one temperaturesensor.
 11. The pneumatic tire with a radio frequency identification(RFID) and tire pressure monitoring system (TPMS) sensor combination ofclaim 1, wherein the integrated RFID and TPMS sensor is a passive unit.12. The pneumatic tire with a radio frequency identification (RFID) andtire pressure monitoring system (TPMS) sensor combination of claim 1,wherein the integrated circuit includes an energy harvester.
 13. Thepneumatic tire with a radio frequency identification (RFID) and tirepressure monitoring system (TPMS) sensor combination of claim 12,wherein the energy harvester harvests power from an electronic field ofan ultra-high frequency radio frequency.
 14. The pneumatic tire with aradio frequency identification (RFID) and tire pressure monitoringsystem (TPMS) sensor combination of claim 12, wherein the energyharvester harvests at least one of optical energy, thermal energy andvibrational energy.
 15. The pneumatic tire with a radio frequencyidentification (RFID) and tire pressure monitoring system (TPMS) sensorcombination of claim 1, wherein the integrated RFID and TPMS sensor ismounted to the innerliner before curing of the tire.
 16. The pneumatictire with a radio frequency identification (RFID) and tire pressuremonitoring system (TPMS) sensor combination of claim 15, wherein thecircuit board is encapsulated in at least one of a rubber compound and apolymer compound.
 17. The pneumatic tire with a radio frequencyidentification (RFID) and tire pressure monitoring system (TPMS) sensorcombination of claim 15, wherein the integrated RFID and TPMS sensor issecured to the innerliner with a strip of innerliner material.
 18. Thepneumatic tire with a radio frequency identification (RFID) and tirepressure monitoring system (TPMS) sensor combination of claim 1, whereinthe integrated RFID and TPMS sensor is mounted to the innerliner aftercuring of the tire.
 19. The pneumatic tire with a radio frequencyidentification (RFID) and tire pressure monitoring system (TPMS) sensorcombination of claim 18, wherein the integrated RFID and TPMS sensor issecured to the innerliner with an adhesive.
 20. The pneumatic tire witha radio frequency identification (RFID) and tire pressure monitoringsystem (TPMS) sensor combination of claim 1, wherein at least one of astress sensor, a strain sensor, a vibration sensor and an accelerometeris mounted on the RFID tag.